10 SCREEN 2
40 INPUT " xmin, xmax, increment ";X1,X2,X4
50 INPUT "ymin, ymax, increment ";Y1,Y2,Y4
55 CLS
60 X5 = - ((X1/(X2-X1))*635)+2
61 IF X1 < 0 AND X2 < 0 THEN X5 =637
62 IF X1> 0 AND X2 > 0 THEN X5 = 2
70 Y5=((Y2/(Y2-Y1))*195)+2
71 IF Y1 < 0 AND Y2< 0 THEN Y5 = 2
72 IF Y1 >0 AND Y2 > 0 THEN Y5 = 197
80 LINE  (X5,Y5) - (X5,2)
90 LINE (X5,Y5 )-(X5,197)
100 LINE (X5,Y5)-(2,Y5)
110 LINE (X5,Y5)-(637,Y5)
120 FOR X3=X5 TO 637 STEP 634 * (X4/(X2- X1))
130 IF X3>637 THEN 160
140 LINE (X3, Y5 -2)-( X3,Y5 +2)
150 NEXT X3
160 FOR X3 = X5 TO 2 STEP -635 *(X4/(X2-X1))
170 IF X3 <2 THEN 200
180 LINE (X3,Y5 - 2 )-(X3,Y5 +2)
190 NEXT X3
200 FOR Y3 = Y5 TO 197 STEP 195 *(Y4/(Y2-Y1))
220         IF Y3 > 195 THEN 250
230 LINE (X5-2,Y3) - (X5 +2,Y3 )
240 NEXT Y3
250 FOR Y3 = Y5 TO 2 STEP - 195 * (Y4 /(Y2 - Y1 ))
260 IF Y3 < 2 THEN 290
270 LINE (X5 - 2, Y3 ) - (X5 +2, Y3)
280 NEXT Y3
281 INPUT " start, finish, increment "      ;X1,X2,X6
284 X=X1
290 Y= SIN(X)
430 PSET((X-X1)*(635/(X2-X1))+2,(-Y     +Y2)*(195/(Y2-Y1))+2)
431 X=X+X6
435 IF X<X2 THEN 290 ELSE 460
460             END
430 PSET((X-X1)*(635/(X2-X1))+2